There are over forty species being commercially produced in Australian aquaculture, most of the production comes from species which can be exported and sold for high prices.

The top five species are tuna, pearl oysters, salmon, edible oysters and prawns. Other species that are of high value or potential include abalones, brackish water or marine fish (barramundi, trouts, snappers, yellowtail kingfish, mulloway, groupers, etc.), mussels, marine sponges, mud crabs and sea cucumbers.

Other important species are freshwater fish (barramundi, trouts, Murray cod, silver perch, jade perch, sleepy cod, etc.)and ornamental fish (for aquaria). These are not covered in this unit.

Top five species in Australia

What makes a species suitable for mariculture?

The two major factors for farming marine species are:

• The profit available from farming the species
• The ease of breeding and growing the species

The profit available from farming the species

This depends on how much it costs to grow the species and how much it can be sold for. Species which are in high demand overseas are the most profitable.

The ease of breeding and growing the species

Other important marine species in Australia

This depends on many factors including:

Established methods being available for breeding the species;

Being able to keep the animals in large numbers in a relatively small space (high population density);

Species which can grow quickly, eat artificial diets and having a good food-conversion ratio. They should also produce a suitable amount of useable food compared to their overall size.

Species which are not aggressive or do not eat each other.

Species which are hardy and resistant to diseases

Species should cause minimal environmental impact if released into the wild. For example, predation or competition with local fauna; changing of genetic make-up or introduction of disease into surrounding populations

Food Conversion ratio

This is a measure of how efficiently an animal can convert its feed into body weight.

Sheep and cattle are not very efficient, it takes about 8 kg of feed for them to increase in weight by 1 kg. Farmed salmon can increase in weight by 1 kg by eating 1.2 kg of feed.

More information on these factors will be available in the case studies of individual species.